Senate Democrats pushed back Monday against Republican promises to repeal the health care overhaul law, urging Speaker-designate John Boehner to back off or jeopardize drug benefits for seniors.

The top five Senate Democratic leaders asked the Ohio Republican in a letter to preserve the health care law or risk leaving seniors without expanded insurance coverage for prescription drugs that was implemented with the law. The incoming House Republican majority has vowed to vote on repealing the law, possibly within days of being sworn in Wednesday.

“As you know, several key provisions of the Patient Protection and Affordable Care Act became effective on January 1, 2011. We write out of concern for one particular measure that addresses a loophole in the Medicare prescription drug benefit,” wrote Senate Majority Leader Harry Reid (Nev.), Majority Whip Dick Durbin (Ill.), Conference Vice Chairman Charles Schumer (N.Y.), Conference Secretary Patty Murray (Wash.) and Policy Committee Vice Chairwoman Debbie Stabenow (Mich.) in a letter dated Monday.

“The incoming House Republican majority that you lead has made the repeal of the federal health care law one of its chief goals,” the Senate Democratic leaders continued in the letter. “We urge you to consider the unintended consequences that the law’s repeal would have on a number of popular consumer protections that help middle class Americans. The ‘donut hole’ fix is just one measure that would be threatened by a repeal effort. Taking this benefit away from seniors would be irresponsible and reckless at a time when it is becoming harder and harder for seniors to afford a healthy retirement.”

The battle over health care reform is expected to re-emerge in the new Congress as Republicans push to repeal it and Democrats attempt to hold the line as the new law continues to be implemented. Full implementation is scheduled to occur by 2014.

Congressional Republicans were unanimous in their opposition of the law when it was approved last year. With recent public opinion polls showing the law’s popularity still under water — and in the aftermath of the Nov. 2 elections — the GOP feels justified in its push to repeal President Barack Obama’s signature domestic policy achievement.

Democrats argue that the law will become more popular as Americans learn about its consumer benefits, including the expansion of the prescription drug benefit for seniors. Republicans have countered the Democrats’ claims by noting that the law cut $500 billion from the Medicare program to help pay for the new health care program.